In this work we have investigated the structural, electric and magnetic properties of KCuO2, along with thermal expansion measurements, from 10 to 420 K. A resistive transition was observed at about 350 K, For comparison, the characteristics and the resistive and magnetic behavior of RbCuO2 and CsCuO2 are also reported. In addition, the importance of substitutional studies on the crystallographic site of K by Cd and Hg is pointed out.